Electromagnet



April 6, 1948.

A. A. AMBROSE ELECTROMAGNET Filed Feb. 26, 1945 E 3 mu a m N 5% Pd 0 v TW m Patented Apr. 6, 1948 UNITED STATES PATENT OFFICE ELECTROMAGNETAnthony A. Ambrose, Dayton, Ohio Application February 26, 1945, SerialNo. 579,735

9 Claims. 1

This invention relates to electrical apparatus and, particularly, tosolenoids.

It is a particular object of the present invention to provide animproved solenoid for actuating an armature.

It is another object to provide a unit solenoid adapted for beingemployed to construct either long or short, or straight or curvedelectromagnetic actuators.

It is still another object to provide a solenoid adapted for combinationwith other like sole-- noids for the construction of relatively longelectromagnetic actuators.

It is another object to provide a relatively long electromagneticactuator comprising a plurality of telescoping unit solenoids ofidentical construction.

These and other objects and advantages of the present invention will bemore fully understood upon reference to the following description inconnection with the accompanying drawings, in which:

Figure 1 is a perspective view of a solenoid constructed according to myinvention;

Figure 2 is a view showing one use of my invention with a plurality ofsolenoids arranged end to end to form a long actuator; and

Figure 3 is a view of another use of my invention.

Referring to the drawings and, in particular to Figure 1, the solenoidwhich comprises the basis of my invention will be seen to comprise acoil having the general configuration of a cone with the smallerstraight portion ID, the conical or tapered portion [2 and the largerstraight portion IA.

The coil is supplied with electrical energy by the leads l6 and I8connected to opposite ends of the said coil.

The outside diameter of the portion I is preferably small enough to beloosely received into the inside of the portion [4 for the purpose ofproviding a long actuator as shown in Figure 2.

The wire forming the coil may be wound on any form suitable for thepurpose and a sleeve of insulating material 20 is preferably placed onthe form prior to the winding so that it becomes an integral part of thewound coil. After winding, the coil may be wrapped, if desired, withfabric or tape and thereafter dipped in insulating enamel and baked.

While the particular proportions of the coil are subject tomodifications, to meet varying conditions, I prefer that the straightportions be of approximately the same length and that the sides of theconical portion be disposed on an angle of approximately 30 from theaxis of the solenoid, as shown.

Referring more particularly to Figure 2, the coils, generally indicatedby the numeral 22 are arranged over a non-magnetic tube 24 intelescoping relationship. The terminals of the coils are connected inparallel to the wires 25 and 28 and a switch 30 provides for theselective energization of the resulting solenoid. Obviously, whether thecoils are connected in parallel, series or series-parallel will bedetermined by the voltage supply available and the voltage for which thecoils are designed.

An armature 32 is provided which is joined by a link 34 to a mechanismto be moved. The armature is positioned at rest as shown in Figure 2 andmoves, when the coils are energized, in the direction indicated by thearrow at 32'. It will be evident that the particular number of coils inthe solenoid is of no moment, and, hence, a solenoid of any length maybe arranged and a stroke of any length obtained.

There are many instances in which such a solenoid would have distinctadvantages and a particular instance would be in the case of aircraftand similar devices where many actuators are required and in which theavailable space is limited. A solenoid constructed according to myinvention would provide an ideal actuator for bomb-bay doors and thelike without having the bulk of the customary hydraulic actuator andwithout utilizing valuable space for connections to a source of power,the wires requiring substantially less space than the connecting pipesor tubes needed for a hydraulic actuator.

In Figure 3 is illustrated a use for my invention similar to that inFigure 2 but showing how the multi-coil solenoid adapts itself to otherthan linear configurations. The arrangement in Figure 3, which isdiagrammatic, is that of a door or window which is to be opened about ahinge and in which it is desired to have a substantially uniform thrust.This is accomplished by shaping the solenoid about the center ofrotation of the movable member and connecting the armature to the memberby a link similarly curved. By means of this arrangement it is possibleto provide a solenoid which acts on an armature that moves in anon-linear path. It is evident that the same unit coil is adapted foruse in either the straight or the curved type'solenoid with equalfacility and that special long or curved solenoids can be constructedwithout the expensive step of winding a special coil to fit theparticular installation.

It will be understood that my invention is capable of modificationaccording to specific needs and uses and, accordingly, it is desired tocomprehend such modifications as may be considered to come within thescope of this disclosure and the appended claims.

Iclaim:

1. As a new article of manufacture, a tubular electromagnetic coilcomprising straight end portions of different diameters and a conicalcentral portion interconnecting said end portions, the thickness of thecoil being substan tially uniform.

2. As a new article of manufacture, an electromagnet coil comprisingcylindrical end portions of difierent diameters and a tapered centralportion interconnecting said end portions,

the thickness of the coil being substantially uniform.

3. As a new article of manufacture, a coil for an electromagnetcomprising straight end portions of different diameters and acentraltapered portion interconnecting said end portions, the

outer diameter of said smaller portion being smaller'than the innerdiameter of said larger portion and the thickness of the coil beingsubstantially uniform.

4.An electromagnetic actuator for moving an armature comprising aplurality of individual coils of uniform thickness connected in paralleland arranged end to end in telescoping relationship, each of the saidcoils comprising straight end portions of different diameters and atapered central portion.

5. The combination in an electromagnetic actuator of an armature adaptedto traverse an arcuate path, a sleeve of the configuration of said pathwithin which said armature is slidable, and a plurality of telescopingunit coils arranged coaxially with said tube and connected in parallel,each of said coils comprising straight cylindrical end portions ofsubstantially equal length and a tapered interconnecting mid portion.

6. An electromagnetic actuator comprising an armature, a tube withinwhich said armature is slidable and a plurality of unit coils mounted onsaid tube in telescoping end to end relationship, each of said coilscomprising straight end portions of equal lengths and different diameterand an intermediate tapered portion interconnecting said end portions,the thickness of the winding of each coil being substantially uniformthroughout the length thereof and the sides of said tapered portionslying at substantially a3 angle from the coil axis.

7. A solenoid comprising a plurality of turns of Wire arranged so as tohave straight end portions of equal lengths and difierent diameters, theouter diameter of the smaller portion being substantially smaller thanthe inner diameter of the larger "portion, and an intermediate conicalportion interconnecting said end portions and the sides thereof makingan included angle of substantially 30 with the solenoid axis.

8. As a new article of manufacture, a hollow coil 'for an electromagnetcomprising straight end portions of difierent dimensions and a centraltapered portion interconnecting said end portions, the outsidedimensions of the smaller of said end portions bein smaller than theinside dimension of the larger of said end portions, and the thicknessof the coil being substantially uniform throughout its length.

9. An electromagnetic actuator for moving an armature comprising aplurality of individual hollow coils adapted for being connected inparallel, series, or series-parallel and arranged end to end intelescoping relationship, each of said coils comprising straight endportions of different dimensions and a tapered central portion.

ANTHONY A. AMBROSE.

REFERENCES: was

The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain Apr, 30, 1923

